<template>
	<el-breadcrumb class="app-breadcrumb" separator="/">
		<transition-group name="breadcrumb">
			<el-breadcrumb-item v-for="(item, index) in levelList" :key="item.path">
				<span
					v-if="
						item.redirect === 'noRedirect' || index === levelList.length - 1
					"
					class="no-redirect"
				>
					{{ item.meta.title }}
				</span>
				<a v-else @click.prevent="handleLink(item)">{{ item.meta.title }}</a>
			</el-breadcrumb-item>
		</transition-group>
	</el-breadcrumb>
</template>

<script>
	import { pathToRegexp } from 'path-to-regexp';

	export default {
		data() {
			return {
				levelList: null
			};
		},
		watch: {
			$route(route) {
				// if you go to the redirect page, do not update the breadcrumbs
				if (route.path.startsWith('/redirect/')) {
					return;
				}
				this.getBreadcrumb();
			}
		},
		created() {
			this.getBreadcrumb();
		},
		methods: {
			getBreadcrumb() {
				// only show routes with meta.title
				let matched = this.$route.matched.filter(
					item => item.meta && item.meta.title
				);
				const first = matched[0];

				if (!this.isDashboard(first)) {
					matched = [
						{ path: '/dashboard', meta: { title: 'Dashboard' } }
					].concat(matched);
				}

				this.levelList = matched.filter(
					item => item.meta && item.meta.title && item.meta.breadcrumb !== false
				);
			},
			isDashboard(route) {
				const name = route && route.name;
				if (!name) {
					return false;
				}
				return (
					name.trim().toLocaleLowerCase() === 'Dashboard'.toLocaleLowerCase()
				);
			},
			pathCompile(path) {
				// To solve this problem https://github.com/PanJiaChen/vue-element-admin/issues/561
				const { params } = this.$route;
				var toPath = pathToRegexp.compile(path);
				return toPath(params);
			},
			handleLink(item) {
				const { redirect, path } = item;
				if (redirect) {
					this.$router.push(redirect);
					return;
				}
				this.$router.push(this.pathCompile(path));
			}
		}
	};
</script>

<style lang="scss" scoped>
	.app-breadcrumb.el-breadcrumb {
		display: inline-block;
		font-size: 14px;
		line-height: 50px;
		margin-left: 8px;

		.no-redirect {
			color: #97a8be;
			cursor: text;
		}
	}
</style>
